Archive | February 26, 2017

Performing a Major Overhaul on NAIAD Stabilizer System

Continuing the work on the 135’ Broward, we have moved on to work on the NAIAD stabilizer system. While NAIAD does not specify an exact interval for performing a major overhaul, it does recommend replacing the lower seals every three years or 4,000 operating hours. Interim service and maintenance should be performed annually but a major overhaul is highly recommended anytime you find water in the grease beyond the outer shaft seals or signs of grease oozing from the inner seals around the shaft.  Once salt water compromises the grease the bearings will start to deteriorate and the grease needs to be replaced

For this project the customer wanted the major overhaul which encompasses removing the fins from the boat, removing the top plate, tiller arm, hoses and shaft. Taking apart the cylinders, inspecting the potentiometer. Basically, the entire system is removed and stripped down.

The upper and roller bearings are installed on the shaft. So when the shaft is removed the roller bearings stay with it. The roller bearings are cut off the shaft in our machine shop, Straight Line Marine. Next the shaft is polished in a lathe and inspected for corrosion or scarring in the lip seal area   . If we do find corrosion, we will clad the corroded area. In this case, we did find corrosion. Once the work on the shaft was complete, we installed new bearings using heat to avoid scoring the shaft.

Cladding shaft

Once the vessel is launched, we will bring up the electronic side of the system and test or reset the potentiometers. It is usually not until this late stage in the project that we can determine if the potentiometers need to be replaced. Once we completed all the steps for this major overhaul, we reassembled the unit and re-installed it back in the boat. The hydraulic stabilizer system on this Broward yacht is good as new and ready to take the captain and crew on more adventures and smooth sailing.

For more information on performing major overhauls on hydraulic stabilizer systems, check out our technical article on the process.